1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor memory device and a semiconductor device, for example, a forming method of fine contact holes continuously aligned in a semiconductor memory device.
2. Description of the Related Art
In recent years, with a demand for a reduction in size and realization of high functions of a semiconductor device, miniaturization of, e.g., a interconnection contact in a semiconductor device has been developed. In a lithography step in manufacture of a semiconductor device, it is known that a linear opening pattern rather than a hole pattern enables forming an elaborate finer pattern because of lithography characteristics. Therefore, by utilizing such characteristics, when forming a fine contact hole a so-called double transfer exposure technology or cross-point exposure technology is used (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 2000-357736 (FIG. 3)). According to this technology, mask layers having linear opening patterns formed therein are superimposed on, e.g., an interlayer insulating layer in such a manner that the linear opening patterns become perpendicular to each other, and an interlayer insulating layer or the like below opening crossing parts of the patterns perpendicular to each other is etched to form each contact hole.
However, in case of exploiting this technology to form each fine contact hole in a semiconductor device, a problem that a fine contact hole is distorted occurs when a resist of, e.g., an organic film is used as a mask to perform etching.